Lewis and Clark had to cross the Nation by canoe and horseback to obtain the information necessary to create the first rudimentary maps the vast Northwest territories of the fledgling United States. Modern "desktop explorers" are not so hindered. Thanks to personal computers and world atlas software, accurate maps of the surface of the Earth can be accessed in seconds from the comfort of one's home or office. Modern atlas software, however, provides much more than accurate maps. Increasingly powerful personal computers and atlas software allow specific locales to be correlated with multimedia features, such as tabular, pictorial, graphical, video, and audio information to reward the desktop explorer with entertaining and informative multimedia visits to far away places.
These multimedia features make computer software "come alive" in an entertaining and user-friendly manner that allows children and adults with only basic computer skills to enjoy and learn as never before. Consumer demand is therefore strong for increasingly entertaining and informative multimedia software. The increasing data storage and processing capabilities of personal computers drive the need for innovation in the development of multimedia atlas software. New computer software techniques are constantly in demand to take advantage of the ever increasing hardware capabilities of personal computers. Much effort therefore goes into improving the speed, accuracy, and content of multimedia atlas software for personal computers.
In a multimedia atlas program, a particular map entity may have an associated set of multimedia features. A particular city, for instance, may have multimedia features such as videos describing the local culture and history, audio clips from famous sporting events and speeches held in the area, pictures from local universities and museums, etc. A user typically selects a multimedia feature by clicking on a control item displayed in a multimedia selection menu. These control items are usually correlated with the map displayed on the monitor. For example, the multimedia control items associated with Chicago are displayed when a map of Chicago is displayed, the multimedia control items associated with the Ohio are displayed when a map of the Ohio is displayed, etc.
Multimedia features are typically associated with significant political or geologic formations, such as continents, bodies of water, countries, regions, cities, mountain ranges, rivers, and so forth. Any particular map view may include all or part of more than one map entity that has associated multimedia features. For example, a map view of a portion of the Great Lakes region might include all or part of the following map entities, each of which has its own set of multimedia features: North America, United States, Canada, Great Lakes region, Michigan, Wisconsin, Illinois, Indiana, Ohio, Lake Michigan, Chicago, Green Bay, and so forth. In fact, the vast majority of map views include more than one map entity that has associated multimedia features. A low-altitude map of Chicago, for instance, displays a portion of North America, the United States, the Great Lakes region, Illinois, Lake Michigan, and Chicago.
Producing atlas software with real-time interactive tools, along with a generous complement of multimedia features, is a challenging task for the computer cartographer. A particularly compelling multimedia experience is produced when the user interacts with the atlas software in real-time by panning or zooming over a map image in response to user commands to simulate flying over the Earth. Such an interactive presentation of map data, together with a generous complement of multimedia features, is both entertaining and informative for users. With this type system, the user may "fly" over the globe from one locale to another, stopping along the way to experience multimedia visits at various locations.
The ability of the user to stop "flying" over virtually any position, orientation, and altitude allows the user to select from a very large number of possible map views. Once the user stops "flying" to select a particular map view, the multimedia atlas program renders the selected map view. Since the user has selected a new map view, it would be advantageous for the multimedia atlas program to update the multimedia selection menu to display the control items associated with the newly displayed map view. But allowing the user to select a map view by panning or zooming may make it difficult to determine which set of the multimedia features to associate with a particular map view.
To illustrate, consider a user who pans to a map view showing a portion of the Great Lakes region. In response, the multimedia selection menu could display the multimedia control items associated with any or all of the map entities in that map view that have associated multimedia features, which may include the World, North America, United States, Canada, Great Lakes region, Michigan, Wisconsin, Illinois, Indiana, Ohio, Lake Michigan, Chicago, Green Bay, etc. Since only a limited number of control items can be displayed at one time, it may not be possible to simultaneously display all of the control items associated with all of these map entities. In addition, prior art multimedia atlas programs are not configured to select a set of multimedia control items to display in association with a map view that has been selected using the panning or zooming tools.
One way to update the multimedia control items to correspond to new map views selected using the panning or zooming tools would be to store a predefined set of multimedia control items for every possible map view. But doing so would require a prohibitively large amount of memory. Prior art multimedia atlas programs, such as ENCARTA96 WORLD ATLAS, address this problem by displaying the multimedia control items for a particular map entity only in association with a best-view map of that locale. Thus, the multimedia control items for the United States are displayed only when the best-view map of the United states is displayed on the monitor, the multimedia control items for the Great Lakes region are displayed only when the best-view map of the Great Lakes region is displayed on the monitor, and so forth.
To facilitate the selection of map entities that have associated multimedia features, these prior art multimedia atlas programs typically include a "find" user interface tool that allows a user to type in the name of a desired map entity. Alternatively, the user may select a desired map entity from an alphabetized scroll list. In response to selection of a map entity using the "find" user interface tool, the best-view map of the selected map entity is displayed along with the multimedia control items for the selected map entity. The user may then select among the multimedia control items while viewing the best-view map of that map entity. If the user pans or zooms away from the best-view map, the multimedia control items are typically disabled.
Thus, if a user pans or zooms to a map view that shows a particular locale, the multimedia control items for the map entities in that map view are not automatically displayed. This limitation occurs because it is difficult for the multimedia atlas program to determine the appropriate context for a map view that a user has panned or zoomed to. That is, since most map view may display all or part of a number of map entities that have associated multimedia features, the multimedia atlas program cannot readily ascertain which control items to display in association with a particular map view. This aspect to the prior art multimedia atlas programs makes the selection of multimedia features cumbersome when the user selects map views using the pan and zoom modes.
Specifically, once a user pans or zooms to a particular map view, the user must then use the "find" user interface tool to fill the multimedia selection menu with the control items associated with a desired map entity. Making this selection replaces the map view with the best-view map of the selected map entity, which typically changes the position, altitude, and orientation of the displayed map view. In fact, selecting a relatively large scale map entity from a relatively low altitude map view, or vice verse, may drastically change the altitude of the map view. For example, selecting the best-view map of the Great Lakes region while viewing a low-altitude map of Chicago would drastically increase the altitude of the map view.
Thus, the prior art procedure for selecting multimedia features from the pan or zoom mode requires several steps, which novice users may not be familiar with. In addition, the procedure for selecting a multimedia feature causes the screen to be repainted with the best-view map of a selected map entity. This may break the continuity of the panning or zooming sequence, and thus diminish the experience of virtually "flying" from one locale to another and enjoying multimedia experiences at the various stops.
Therefore, there is a need for a multimedia atlas program that automatically associates multimedia control items with map views selected using a panning or zooming tool. There is a further need for a multimedia atlas program that automatically associates multimedia control items with map views without repainting the screen with the best-view map of a particular map entity.